Magnetic resonance techniques will be used to study the structure and function of (binding, catalysis, allosteric cooperativity, transmission of nerve impulses, immune response) molecules and systems of biological importance. These include: molecules such as terpenes, steroids, nucleotides, vitamins; simple proteins such as serine proteases, pepsin, lysozyme; multisubunited proteins such as hemoglobin and glyceraldehyde-3-phosphate dehydrogenase; biological systems such as membranes, erythrocytes, immune response.